1 /* 2 * net/sched/cls_basic.c Basic Packet Classifier. 3 * 4 * This program is free software; you can redistribute it and/or 5 * modify it under the terms of the GNU General Public License 6 * as published by the Free Software Foundation; either version 7 * 2 of the License, or (at your option) any later version. 8 * 9 * Authors: Thomas Graf <tgraf@suug.ch> 10 */ 11 12 #include <linux/module.h> 13 #include <linux/slab.h> 14 #include <linux/types.h> 15 #include <linux/kernel.h> 16 #include <linux/string.h> 17 #include <linux/errno.h> 18 #include <linux/rtnetlink.h> 19 #include <linux/skbuff.h> 20 #include <net/netlink.h> 21 #include <net/act_api.h> 22 #include <net/pkt_cls.h> 23 24 struct basic_head { 25 u32 hgenerator; 26 struct list_head flist; 27 }; 28 29 struct basic_filter { 30 u32 handle; 31 struct tcf_exts exts; 32 struct tcf_ematch_tree ematches; 33 struct tcf_result res; 34 struct list_head link; 35 }; 36 37 static const struct tcf_ext_map basic_ext_map = { 38 .action = TCA_BASIC_ACT, 39 .police = TCA_BASIC_POLICE 40 }; 41 42 static int basic_classify(struct sk_buff *skb, const struct tcf_proto *tp, 43 struct tcf_result *res) 44 { 45 int r; 46 struct basic_head *head = (struct basic_head *) tp->root; 47 struct basic_filter *f; 48 49 list_for_each_entry(f, &head->flist, link) { 50 if (!tcf_em_tree_match(skb, &f->ematches, NULL)) 51 continue; 52 *res = f->res; 53 r = tcf_exts_exec(skb, &f->exts, res); 54 if (r < 0) 55 continue; 56 return r; 57 } 58 return -1; 59 } 60 61 static unsigned long basic_get(struct tcf_proto *tp, u32 handle) 62 { 63 unsigned long l = 0UL; 64 struct basic_head *head = (struct basic_head *) tp->root; 65 struct basic_filter *f; 66 67 if (head == NULL) 68 return 0UL; 69 70 list_for_each_entry(f, &head->flist, link) 71 if (f->handle == handle) 72 l = (unsigned long) f; 73 74 return l; 75 } 76 77 static void basic_put(struct tcf_proto *tp, unsigned long f) 78 { 79 } 80 81 static int basic_init(struct tcf_proto *tp) 82 { 83 struct basic_head *head; 84 85 head = kzalloc(sizeof(*head), GFP_KERNEL); 86 if (head == NULL) 87 return -ENOBUFS; 88 INIT_LIST_HEAD(&head->flist); 89 tp->root = head; 90 return 0; 91 } 92 93 static void basic_delete_filter(struct tcf_proto *tp, struct basic_filter *f) 94 { 95 tcf_unbind_filter(tp, &f->res); 96 tcf_exts_destroy(tp, &f->exts); 97 tcf_em_tree_destroy(tp, &f->ematches); 98 kfree(f); 99 } 100 101 static void basic_destroy(struct tcf_proto *tp) 102 { 103 struct basic_head *head = tp->root; 104 struct basic_filter *f, *n; 105 106 list_for_each_entry_safe(f, n, &head->flist, link) { 107 list_del(&f->link); 108 basic_delete_filter(tp, f); 109 } 110 kfree(head); 111 } 112 113 static int basic_delete(struct tcf_proto *tp, unsigned long arg) 114 { 115 struct basic_head *head = (struct basic_head *) tp->root; 116 struct basic_filter *t, *f = (struct basic_filter *) arg; 117 118 list_for_each_entry(t, &head->flist, link) 119 if (t == f) { 120 tcf_tree_lock(tp); 121 list_del(&t->link); 122 tcf_tree_unlock(tp); 123 basic_delete_filter(tp, t); 124 return 0; 125 } 126 127 return -ENOENT; 128 } 129 130 static const struct nla_policy basic_policy[TCA_BASIC_MAX + 1] = { 131 [TCA_BASIC_CLASSID] = { .type = NLA_U32 }, 132 [TCA_BASIC_EMATCHES] = { .type = NLA_NESTED }, 133 }; 134 135 static int basic_set_parms(struct net *net, struct tcf_proto *tp, 136 struct basic_filter *f, unsigned long base, 137 struct nlattr **tb, 138 struct nlattr *est) 139 { 140 int err = -EINVAL; 141 struct tcf_exts e; 142 struct tcf_ematch_tree t; 143 144 err = tcf_exts_validate(net, tp, tb, est, &e, &basic_ext_map); 145 if (err < 0) 146 return err; 147 148 err = tcf_em_tree_validate(tp, tb[TCA_BASIC_EMATCHES], &t); 149 if (err < 0) 150 goto errout; 151 152 if (tb[TCA_BASIC_CLASSID]) { 153 f->res.classid = nla_get_u32(tb[TCA_BASIC_CLASSID]); 154 tcf_bind_filter(tp, &f->res, base); 155 } 156 157 tcf_exts_change(tp, &f->exts, &e); 158 tcf_em_tree_change(tp, &f->ematches, &t); 159 160 return 0; 161 errout: 162 tcf_exts_destroy(tp, &e); 163 return err; 164 } 165 166 static int basic_change(struct net *net, struct sk_buff *in_skb, 167 struct tcf_proto *tp, unsigned long base, u32 handle, 168 struct nlattr **tca, unsigned long *arg) 169 { 170 int err; 171 struct basic_head *head = (struct basic_head *) tp->root; 172 struct nlattr *tb[TCA_BASIC_MAX + 1]; 173 struct basic_filter *f = (struct basic_filter *) *arg; 174 175 if (tca[TCA_OPTIONS] == NULL) 176 return -EINVAL; 177 178 err = nla_parse_nested(tb, TCA_BASIC_MAX, tca[TCA_OPTIONS], 179 basic_policy); 180 if (err < 0) 181 return err; 182 183 if (f != NULL) { 184 if (handle && f->handle != handle) 185 return -EINVAL; 186 return basic_set_parms(net, tp, f, base, tb, tca[TCA_RATE]); 187 } 188 189 err = -ENOBUFS; 190 f = kzalloc(sizeof(*f), GFP_KERNEL); 191 if (f == NULL) 192 goto errout; 193 194 err = -EINVAL; 195 if (handle) 196 f->handle = handle; 197 else { 198 unsigned int i = 0x80000000; 199 do { 200 if (++head->hgenerator == 0x7FFFFFFF) 201 head->hgenerator = 1; 202 } while (--i > 0 && basic_get(tp, head->hgenerator)); 203 204 if (i <= 0) { 205 pr_err("Insufficient number of handles\n"); 206 goto errout; 207 } 208 209 f->handle = head->hgenerator; 210 } 211 212 err = basic_set_parms(net, tp, f, base, tb, tca[TCA_RATE]); 213 if (err < 0) 214 goto errout; 215 216 tcf_tree_lock(tp); 217 list_add(&f->link, &head->flist); 218 tcf_tree_unlock(tp); 219 *arg = (unsigned long) f; 220 221 return 0; 222 errout: 223 if (*arg == 0UL && f) 224 kfree(f); 225 226 return err; 227 } 228 229 static void basic_walk(struct tcf_proto *tp, struct tcf_walker *arg) 230 { 231 struct basic_head *head = (struct basic_head *) tp->root; 232 struct basic_filter *f; 233 234 list_for_each_entry(f, &head->flist, link) { 235 if (arg->count < arg->skip) 236 goto skip; 237 238 if (arg->fn(tp, (unsigned long) f, arg) < 0) { 239 arg->stop = 1; 240 break; 241 } 242 skip: 243 arg->count++; 244 } 245 } 246 247 static int basic_dump(struct tcf_proto *tp, unsigned long fh, 248 struct sk_buff *skb, struct tcmsg *t) 249 { 250 struct basic_filter *f = (struct basic_filter *) fh; 251 struct nlattr *nest; 252 253 if (f == NULL) 254 return skb->len; 255 256 t->tcm_handle = f->handle; 257 258 nest = nla_nest_start(skb, TCA_OPTIONS); 259 if (nest == NULL) 260 goto nla_put_failure; 261 262 if (f->res.classid && 263 nla_put_u32(skb, TCA_BASIC_CLASSID, f->res.classid)) 264 goto nla_put_failure; 265 266 if (tcf_exts_dump(skb, &f->exts, &basic_ext_map) < 0 || 267 tcf_em_tree_dump(skb, &f->ematches, TCA_BASIC_EMATCHES) < 0) 268 goto nla_put_failure; 269 270 nla_nest_end(skb, nest); 271 272 if (tcf_exts_dump_stats(skb, &f->exts, &basic_ext_map) < 0) 273 goto nla_put_failure; 274 275 return skb->len; 276 277 nla_put_failure: 278 nla_nest_cancel(skb, nest); 279 return -1; 280 } 281 282 static struct tcf_proto_ops cls_basic_ops __read_mostly = { 283 .kind = "basic", 284 .classify = basic_classify, 285 .init = basic_init, 286 .destroy = basic_destroy, 287 .get = basic_get, 288 .put = basic_put, 289 .change = basic_change, 290 .delete = basic_delete, 291 .walk = basic_walk, 292 .dump = basic_dump, 293 .owner = THIS_MODULE, 294 }; 295 296 static int __init init_basic(void) 297 { 298 return register_tcf_proto_ops(&cls_basic_ops); 299 } 300 301 static void __exit exit_basic(void) 302 { 303 unregister_tcf_proto_ops(&cls_basic_ops); 304 } 305 306 module_init(init_basic) 307 module_exit(exit_basic) 308 MODULE_LICENSE("GPL"); 309 310